This invention relates to aircraft pilots' helmets and in particular to custom fitted helmets which are formed by a foaming process in situ.
Conventional pilot helmets have several drawbacks; they are generally ill-fitting, tend to become unbalanced during severe aircraft maneuvers and are undesirably heavy. These drawbacks are made less tolerable by the present day trend of using the helmet as an instrumentation platform. To help overcome these deliterious qualities, prior art practice has been directed toward providing most pilots with custom fitted helmets. Several approaches have been used in the past to form custom fitted helmets. One approach entails molding a pilot's head for a factory produced, head molded liner which is trimmed, padded, covered and thereafter inserted into the helmet proper. Another approach used in the prior art is to attach to the inside of a helmet shell several flattened tubes filled with an initially flexible material and to mount the tubeshell assembly on the pilot's head. The material within the tube hardens after a time and conforms to the pilot's head shape. This latter method is objectionable because the liner so formed contacts the head at relatively few contact points; after extended wear, the helmet weight bearing on these few contact points makes wearing of the helmet extremely uncomfortable. Both of the aforesaid techniques are unsatisfactory because they are generally cumbersome, time-consuming and usually result in an uncomfortably hot helmet because no provisions are made for air circulation within the helmet. More importantly these techniques employ equipment and methods which are ill-suited to constructing a helmet under field conditions.